1. Field of the Invention
Embodiments of the present invention generally relate to the fabrication of photovoltaic devices. In particular, the present invention relates to methods for patterning and metalizing photovoltaic devices.
2. Description of the Related Art
Solar cells are photovoltaic devices that convert sunlight directly into electrical power. The most common solar cell material is silicon, which may be in the form of single or multicrystalline substrates, sometimes referred to as wafers. Because the amortized cost of forming silicon-based solar cells to generate electricity is higher than the cost of generating electricity using traditional methods, there has been an effort to reduce the cost of forming solar cells.
Various approaches enable fabricating current carrying metal lines, or conductors, on solar cells. One prior art method of fabricating the current carrying metal lines in solar cell devices uses a screen printing process in which a metal paste is deposited in a desired pattern on a substrate surface and then annealed. However, several drawbacks exist with this manufacturing method. Current screen printing processes produce grids with broad line widths resulting in a substantial amount of shading of the surface of the solar cell. Additionally, current screen printing pastes contain a substantial amount of frit resulting in high sheet resistance of the metal and high contact resistance to the emitter and base of the solar cell. Further, screen printing metal paste on the relatively thin substrates used in solar cell manufacturing can cause physical damage to the substrate resulting in a lower device yield and corresponding increase in the cost of ownership of the fabrication process.
Therefore, a need for improved methods for forming patterned conductive lines on a surface of a solar cell is needed.